1. Technical Field
This invention relates to cell culture apparatus for growing animal cells in rotating cylinders, or roller bottles.
2. Description of the Background Art
There are a variety of existing types of apparatus in which cells are cultured whilst attached to the interior of substantially horizontally mounted cylinders or bottles which are slowly rotated to ensure that all the cells are regularly bathed in culture media.
In order to increase the productivity of the apparatus, a plurality of bottles or cylinders may be connected together via a common fluid supply/extraction manifold thus allowing fluid to be transferred into or out of a number of vessels simultaneously.
It is essential in such a system to ensure that each vessel is provided with an equal volume of fluid during processing operations. In some systems, for example, U.S. Pat. No. 3,847,749, or WO 96/05285 (EU 0775196), equal fluid distribution is accomplished by means of a multi-channel peristaltic pump, with each vessel being assigned one channel of the pump. Such systems allow the bottles to processed in situ and in the horizontal position.
In other systems, for example U.S. Pat. No. 3,827,943, or U.S. Pat. No. 3,732,149 a drum or rotor housing a plurality of interconnected cylindrical vessels is tilted into the vertical position during fluid transfer operations, thus allowing the fluid level in each vessel to equalize by gravity. This has the advantage of simplicity over systems that require a separate pumping channel for each vessel. Unfortunately, the existing arrangements of tilting rotor devices require air and fluid connections to be provided at opposite ends of the vessels, and cannot therefore utilize conventional roller bottles which are readily available, sterile irradiated, in standardized sizes. It would be advantageous if this type of apparatus could be adapted to utilize standard roller bottles.
Accordingly a first aspect of the present invention provides cell culture apparatus comprising a rotor releasably housing a plurality of cell culture vessels/roller bottles and with means provided to allow rotation of the rotor at a controlled speed about a substantially horizontal axis for cell incubation purposes, with further means provided to allow the rotational axis of the said rotor and bottles housed therein to be tilted to a substantially vertical position such that a cap end of the bottles is lowermost, each bottle being provided with a cap equipped with a fluid supply/drain connection arranged at the lowest point of the cap when said bottle is disposed inverted with the cap lowermost, a manifold with one or more sealable external connections and a plurality of connections communicating with the fluid supply/drain connection of each bottle cap, with venting of the gas space within the bottle during fluid transfer being provided by means of a snorkel tube passing upwards through fluid in the inverted position and formed as an internal extension of the bottle cap, said snorkel tube extending into the body of the bottle and having an end opening into the body of the bottle at a position clear of fluid in the bottle in either the substantially vertical or horizontal directions thereof, the said snorkel tube being further provided with microporous venting means to atmosphere, the arrangement of the parts being such that fluid transfer into or out of the bottles is accomplished via the said manifold external connection whilst the rotor and bottles are in the substantially vertically inverted position.
Another aspect of the invention provides a roller bottle cap, adapted to allow fluid transfer into or out of a roller bottle whilst said bottle is inverted substantially vertically, comprising a fluid supply/drain connection arranged at the lowest point of the cap when said bottle is vertically inverted, with venting of the gas space above the fluid during fluid transfer being provided by means of a snorkel tube extending upwards through the fluid, said snorkel tube having an end opening into the body of the bottle at a position clear of the fluid therein.
More particularly, the snorkel tube is arranged to extend substantially along the central longitudinal axis of the bottle.
Preferably the snorkel tube is provided with graduations along the length thereof to indicate the volume of fluid contained within the bottle when orientated vertically. Preferably the end of the snorkel opening into the bottle is provided with a fluid trap.